The invention relates to a method of and apparatus for controlling a picture signal processing mode. The picture signal processing mode may indicate whether the picture signal originates from movie-film and, more specifically, how the fields of the picture signal relate to the pictures of the movie-film, or whether motion vectors are reliable enough to allow for a motion-compensated picture signal processing mode. The invention further relates to a television signal receiver including such a picture signal processing mode controlling apparatus.
Many recent proposals for novel High-Definition TeleVision (HDTV) systems include the requirement that a control signal is to be transmitted along with the HDTV signal which gives an indication about the origin of the picture signal, because in some respects, picture signals originating from movie-film require a different treatment, i.e. picture signal processing mode, than picture signals which are picked up by a video camera from a live scene and transmitted directly or recorded on tape or disc and subsequently transmitted as the picture signal, herein termed "non-movie-film picture signals". For similar reasons, up-conversion algorithms to be used in Improved Definition TeleVision (IDTV) receivers require a picture signal processing mode control signal which provides information about the origin of the picture signal. Up till now, no reliable and yet simple method of automatically detecting whether the picture signal originates from movie-film has been reported. Another problem met in IDTV receivers is that motion-compensated picture signal processing methods are potentially very suitable to provide an improved display quality of the picture signal, but that artifacts caused by motion vector estimation errors are very disturbing. Consequently, there is a need to determine when motion vectors are reliable enough to allow for a motion-compensated picture signal processing mode, and when the motion-compensated picture signal processing mode should be switched off in view of the unreliability of the motion vectors.